A fully sprinklered structure containing 1,500 sprinklers requires a minimum supply of how many spare sprinklers?

According to NFPA 13, Standard for the Installation of Sprinkler Systems, a specific quantity of spare sprinklers must be maintained on the premises. The required number is based on the total quantity of sprinklers installed. For a system with over 1,000 sprinklers, the standard mandates a minimum of 24 spare sprinklers. Since the facility has 1,500 installed sprinklers, it falls into this category. The stock of spare sprinklers must include all types and temperature ratings installed in the property to ensure any damaged or operated sprinkler can be promptly replaced, maintaining the system's operational readiness.

A. 6: This is the minimum number of spare sprinklers required for a system with fewer than 300 sprinklers.

B. 12: This is the minimum number of spare sprinklers required for a system with 300 to 1,000 sprinklers.

C. 18: This quantity is not a specified minimum threshold for spare sprinklers according to the NFPA 13 standard.

1. NFPA 13, Standard for the Installation of Sprinkler Systems, 2022 Edition. Section 19.2.8.2, "Spare Sprinklers." Table 19.2.8.2 specifies:

Fewer than 300 sprinklers: 6 spares

300 to 1000 sprinklers: 12 spares

Over 1000 sprinklers: 24 spares

2. Cote, A. E. (Ed.). (2008). Fire Protection Handbook (20th ed., Vol. 2). National Fire Protection Association. Section 12, Chapter 2, "Water-Based Fire Protection Systems," p. 12-38. The handbook reiterates the spare sprinkler requirements as stipulated in NFPA 13.

3. Oklahoma State University, College of Engineering, Architecture and Technology. (n.d.). FPST 3333: Fire Sprinkler and Standpipe Systems [Courseware]. The course curriculum covers NFPA 13 installation requirements, including the specific spare sprinkler quantities outlined in the standard.